Unfortunately I've no idea how to tell YaST that you installed something from source (oh how I hate RPM!!!). I don't think you should have installed from source personally, with an RPM based distro its good practice to stick to RPM (saves your machine getting in a mess!).
Anyhow on to the more important stuff (setting up apache), I gotta warn you now I'm no apache guru, I have only one website running on my apache but there's nothing to stop you adding more! First port of call is the apache documentation, this sounds tedious I know but you will actually learn something and make life much easier on yourself, if you go to localhost you should be able to get to the documentation from there. The docs are really rather good and should be the first place to look to do something. As far as getting hosts up and running on apache, I've never used a GUI but I imagine a search on google should throw up lots of results for this!
If you want to do it the good ol' fashioned way (I prefer this since I then have some vague idea what's going on) then you need to open up a terminal and become superuser (su) and then type:
gedit (or pico, whatever your preferred editor is, i like VI personally) /etc/apache2/httpd.conf
right near the bottom of the file is the VirtualHosts bit, there's an example in there that you should be able to work out how to adapt to what you want. for my simple website (I only use it for testing on my localmachine) I have the following:
this means any request on port 80 is going to this website, hope this helps a little bit!